Orientation Manipulation and Defect Passivation for Perovskite Solar Cells by a Natural Compound.

Different facets in perovskite crystals exhibit distinct atomic arrangements, influencing their electronic, physical, and chemical properties. Perovskite films incorporating tin oxide (SnO2) as the electron transport layer face challenges in facet regulation. This study reveals that tea saponin (TS), a natural compound serves as a SnO2 modifier, facilitates optimal growth of perovskite crystals on the (111) facet. The modification promotes preferential crystal orientation through hydrogen bond and Lewis coordination. TS forms a chelate with SnO2, resulting in a smoother film and n-type doping, leading to improved carrier extraction and reduced defects. The TS-modified perovskite solar cells achieve a champion efficiency of 24.2%, leveraging from an obvious enhancement of open-circuit voltage (Voc) of 1.18 V and fill factor (FF) of 82.8%. The devices also demonstrate enhanced humidity tolerance and storage stability, ensuring improved stability without encapsulation.

A comprehensive analysis of library preparation methods shows high heterogeneity of extrachromosomal circular DNA but distinct chromosomal amount levels reflecting different cell states.

Extrachromosomal circular DNA (eccDNA) was discovered several decades ago, but little is known about its function. With the development of sequencing technology, several library preparation methods have been developed to elucidate the biogenesis and function of eccDNA. However, different treatment methods have certain biases that can lead to their erroneous interpretation. To address these issues, we compared the performance of different library preparation methods. Our investigation revealed that the utilization of rolling-circle amplification (RCA) and restriction enzyme linearization of mitochondrial DNA (mtDNA) significantly enhanced the efficiency of enriching extrachromosomal circular DNA (eccDNA). However, it also introduced certain biases, such as an unclear peak in ∼160-200 bp periodicity and the absence of a typical motif pattern. Furthermore, given that RCA can lead to a disproportionate change in copy numbers, eccDNA quantification using split and discordant reads should be avoided. Analysis of the genomic and elements distribution of the overall population of eccDNA molecules revealed a high correlation between the replicates, and provided a possible stability signature for eccDNA, which could potentially reflect different cell lines or cell states. However, we found only a few eccDNA with identical junction sites in each replicate, showing a high degree of heterogeneity of eccDNA. The emergence of different motif patterns flanking junctional sites in eccDNAs of varying sizes suggests the involvement of multiple potential mechanisms in eccDNA generation. This study comprehensively compares and discusses various essential approaches for eccDNA library preparation, offering valuable insights and practical advice to researchers involved in characterizing eccDNA.

Influence of Different Pt Functionalization Modes on the Properties of CuO Gas-Sensing Materials.

The functionalization of noble metals is an effective approach to lowering the sensing temperature and improving the sensitivity of metal oxide semiconductor (MOS)-based gas sensors. However, there is a dearth of comparative analyses regarding the differences in sensitization mechanisms between the two functionalization modes of noble metal loading and doping. In this investigation, we synthesized Pt-doped CuO gas-sensing materials using a one-pot hydrothermal method. And for Pt-loaded CuO, Pt was deposited on the synthesized pristine CuO surface by using a dipping method. We found that both functionalization methods can considerably enhance the response and selectivity of CuO toward NO2 at low temperatures. However, we observed that CuO with Pt loading had superior sensing performance at 25 °C, while CuO with Pt doping showed more substantial response changes with an increase in the operating temperature. This is mainly due to the different dominant roles of electron sensitization and chemical sensitization resulting from the different forms of Pt present in different functionalization modes. For Pt doping, electron sensitization is stronger, and for Pt loading, chemical sensitization is stronger. The results of this study present innovative ideas for understanding the optimization of noble metal functionalization for the gas-sensing performance of metal oxide semiconductors.

Observation of Hot Carrier Localization Affected by A Cations in Hybrid Perovskites.

Organic-inorganic lead halide perovskites (OLHPs) have demonstrated exceptional properties in high-performance photoelectric devices. However, the impact of A-site cations, specifically formamidinium and methylammonium (MA), on the optoelectronic properties of OLHPs, particularly in the context of hot carrier utilization, remains a topic of debate. In this study, we propose a method for characterizing hot carrier transportation by measuring the hot carrier mobility and momentum-dependent transient photocurrent influenced by A-site cations in OLHPs. Our findings reveal that the direction of photon drag current is reversed upon substitution of the MA cation, suggesting the strong localization of hot carriers by the MA cation dipole. Furthermore, the correlation between the hot carrier photoconductivity and the electronic structure in different A-site cation samples indicates that hot carrier mobility in OLHPs can be reduced by >50% due to the influence of A-site cations.

SnO2 Interacted with Sodium Thiosulfate for Perovskite Solar Cells over 25% Efficiency.

Tin oxide (SnO2) as electron transportation layer (ETL) has demonstrated remarkable performance applied in perovskite solar cells but still accommodated a host of defects such as oxygen vacancies, uncoordinated Sn4+ , and absorbed hydroxyl groups. Here, we use inorganic sodium thiosulfate Na2S2O3 to modify SnO2 nanoparticles in a bulk blending manner. Strong interaction between Na2S2O3 and SnO2 occurs, as reflected from the elemental chemical state change. The interaction has endowed the SnO2 film with better uniformity, increased conductivity, and more matched energy level with perovskite. Moreover, the modified SnO2 film as a substrate could promote the crystallization of perovskite by suppressing unreacted residual PbI2. The trap density from perovskite bulk to the SnO2 film across their interface has been effectively reduced, thus inhibiting the nonradiative recombination and promoting the transportation and extraction of charge carriers. Finally, the solar cell based on modified SnO2 has achieved a champion efficiency of 25.2%, demonstrating the effectiveness and potential of sulfur-containing molecules on optimizing the SnO2 property.

Integrated analysis of mRNA and extrachromosomal circular DNA profiles to identify the potential mRNA biomarkers in breast cancer.

Extrachromosomal circular DNAs (eccDNAs) have been proved an inseparable relationship with cancer, based on the biological mechanisms of its biogenesis and impact on tumorigenesis, but still lacked of methods to analyze its function on the pathogenesis and progression of breast cancer (BC). The mRNA and eccDNA from BC cell samples (MDA-MB-453 and MCF-12A) were extracted with the removal of rRNA and linear DNA, respectively. High-throughput sequencing and bioinformatics analysis were performed to explore their expression level and molecular characterization of eccDNA. A total number of 161,062 eccDNA ranging from 33 bp to 54229 bp were detected with a median size of 1143 bp, distributed on all chromosomes and enriched on chromosome 20 the most. EccDNAs located in exons, upstream and downstream 2 kb regions were significantly increased compared with background. Analysis of eccDNA-related differentially expressed genes (eccDEGs) showed that FAT2 properly separated the two cells. CTNNB1, CACNA2D2 and CACNA1D were the hub genes with higher degrees in critical modules. All these four genes were significantly differentially expressed between breast invasive carcinoma (BRCA) tissues and normal ones. FAT2 and CTNNB1 correlated with significantly different overall survival (OS) when differentially expressed. The four genes showed a strong correlation with each other significantly and changed between tumor and normal samples. The results showed the potential of FAT2, CTNNB1, CACNA2D2 and CACNA1D as biomarkers with analysis of both DEGs and eccDEGs, which might assist in clinical medical treatment.

N, P and S co-doped carbon materials derived from polyphosphazene for enhanced selective U(VI) adsorption.

Herein, the precursor polyphosphazene was synthesized by the polymerization of hexachlorocyclotriphosphazene (HCCP) and bis(4-hydroxyphenyl) sulfone (BPS). The adsorbent which was codoped with N, P and S (amidate-CS) was developed from the precursor by using the carbonization method. The images of Scanning electron microscope (SEM) and Transmission electron microscope (TEM) indicate that the amidate-CS possessed porous graphene-like carbon lamellar structure. The excellent behaviors with respect to kinetics (120 min for equilibrium) and thermodynamics (maximum removal of 290 mg/g when pH was at 6.0) revealed the outstanding performance of amidate-CS in removing U(VI), which is due to the functional groups and strong covalent bonds between heteroatoms and uranyl ions. The adsorption of amidate-CS followed the pseudo-second-order kinetic and Langmuir adsorption model. The thermodynamic parameters indicate that the process was spontaneous and endothermic. The adsorption and desorption efficiency of amidate-CS had a slight decrease after five cycles, indicating excellent regeneration performance. Overall, the amidate-CS is a prospective candidate for highly selective U(VI) removing.

[Treatment of spoke heel injuries in children].

OBJECTIVE: To evaluate the characteristics, classification, treatment methods, and clinical outcomes of the spoke heel injuries in children. METHODS: From June 2001 to June 2008, 289 children with bicycle or motorcycle spoke heel injuries were treated, including 179 males and 110 females aged 2-12 years old (average 3.9 years old). There were 179 cases of skin contusion and laceration (type I), 83 cases of skin and soft tissue defect with Achilles tendon exposure (type II), and 27 cases of wide skin and soft tissue defect with the Achilles tendon defect and rupture (type III). The defect size of the skin or the soft tissues ranged from 3 cm x 2 cm to 11 cm x 7 cm in type II and type III injury. The time between injury and hospital admission was 1-53 days (average 14.5 days). Child patients with type I injury were managed with dressing or suturing after debridement. For the child patients with type II injury, the wound was repaired with the regional fascia flap in 53 cases, the reverse sural neurocutaneous vascular flap in 19 cases, the reverse saphenous neurocutaneous vascular flap in 9 cases, and the lateral supramalleolar flap in 2 cases. For the child patients with type III injury, 6 cases underwent primary repair of the Achilles tendon followed by the transposition of the reverse sural neurocutaneous vascular flap, 3 cases received primary repair of the wound with the reverse sural neurocutaneous vascular flap and secondary reconstruction of the Achilles tendon with the upturned fascia strip or the ipsilateral iliotibial tract transplant, and 18 cases underwent primary repair of the wound and the Achilles tendon with the sliding bi-pedicled gastrocnemius musculocutaneous flap. The flap size ranged from 4 cm x 2 cm to 30 cm x 12 cm. All the donor sites were closed by partial suture and split-thickness skins graft. The lower limbs were immobilized with plaster splints after operation. RESULTS: All the flaps survived except for 1 case of type II suffering from distal flap venous crisis 3 days after operation and 6 cases of type III suffering from distal flap necrosis 3-5 days after operation. All those flaps survived after symptomatic treatment. All the skin grafts at the donor site survived uneventfully. All the wounds healed by first intention. All child patients were followed up for 15-820 days (average 42 days). Child patients with type I and type II injury had a full recovery of ankle functions. While 25 cases of type III injury had ankle dorsal extension degree loss (10-30 degrees) and unilateral plantar flexion strength decrease 3 months after operation without influence on walking, and 2 cases recovered well. CONCLUSION: Spoke heel injury in children has special mechanisms of injury, and the choice of proper treatment method should be based on the types of injury.